Hackers are breaking into websites that run vulnerable versions of the popular blogging software WordPress, according to several cybersecurity firms. One estimate puts the number of vulnerable WordPress websites at tens of millions as of Monday.
Last week, WordPress patched two critical security flaws, urging people who run its software on their websites to update it “immediately.” The vulnerabilities are so severe that WordPress enabled forced updates where possible. Since then, cybersecurity companies Patchstack, Hexastrike, and WatchTowr have all warned that hackers are exploiting the vulnerabilities in the wild, meaning they are taking over websites that are still running susceptible versions of WordPress.
It’s unclear how many WordPress-powered websites on the internet are at risk, but it’s possible to make some educated guesses. The vulnerable versions of WordPress are 6.9.0 through 6.9.4, and 7.0.0 to 7.0.1. According to WordPress’ official stats, there are more than 400 million websites that run those flawed versions, although these statistics likely don’t reflect websites that have recently been patched.
Cybersecurity consultant Daniel Card, who told TechCrunch that he looked at a sample of around 4,200 WordPress websites, estimates that less than 15% are vulnerable. Applying Card’s projection across the total population of WordPress websites on the internet, the total figure would still be around 90 million.
The researcher credited WordPress with pushing automatic updates, Cloudflare with blocking attacks against vulnerable websites, and websites using cybersecurity protections such as web firewalls for the limited number of sites that could currently be hacked.
Automattic, as well as WordPress.org, the project that develops WordPress’ open-source code, did not immediately respond to a request for comment.
One of the critical WordPress bugs was found and reported by Adam Kues of cybersecurity firm Searchlight Cyber, which dubbed it WP2Shell. Paired with the other bug, hackers can take full remote control of vulnerable websites.
